As a radio frequency signal transceiver, a radio base station is configured to amplify an input signal by using a power amplifier (PA for short), and transmit the amplified input signal by using a transmitter. A power amplifier is a component consuming most power in a radio base station, and efficiency of the power amplifier directly affects power consumption of the entire radio base station.
A Doherty power amplifier is usually used in an existing radio base station, to reduce power consumption of the radio base station.
The Doherty power amplifier includes a primary power amplifier and at least one peak power amplifier. The primary power amplifier is connected in parallel to each peak power amplifier. A working principle of the Doherty power amplifier is that the primary power amplifier and each peak power amplifier can work in saturation regions thereof by using an active-load pulling technology, thereby ensuring that the entire Doherty power amplifier has relatively high efficiency within an input power range as large as possible.
In a process of implementing the present application, the inventor finds that the prior art has at least the following problem.
If a Doherty power amplifier having the existing architecture is used, to maintain high efficiency, a corresponding input power changing range is relatively small, and power consumption increases when the input power changing range is relatively large. This cannot meet a requirement of a radio base station for power consumption.